1. Field of the invention
The present invention relates to a self configurable, dual bridge, power amplifier having a considerably reduced consumption as compared with a dual bridge amplifier of a conventional type, for the same output power rating.
2. Discussion of the Related Art
In many applications and particularly in audio equipments, the low frequency, power amplifiers that drive the loudspeakers very often have a so-called bridge configuration. When employing integrated amplifiers in such a configuration, it is possible to achieve an output power rating of about 20W as compared to an output power of about 5W that could be obtained by the same integrated amplifiers in a single-ended configuration.
On the other hand, the output power stages of car radios or of comparable audio systems often have four "channels": right-front, left-front, right-rear and left-rear, in order to permit a uniform sound diffusion in the compartment by adjusting attenuation on the different channels.
Four, 20W, power amplifiers imply a maximum power dissipation which may be about 4.times.12=48W. Because of a required compactness of car radio and similar audio systems, such a power can hardly be dissipated if not on account of a relatively high internal temperature of the apparatus. On the other hand, a high working temperature may be detrimental for the magnetic tape of a cassette or for an optical compact disk (CD), the drives of which are often installed inside a single cabinet of the audio apparatus.
From the above considerations, it is clear that there is a need or utility for a bridge amplifier having a substantially reduced dissipation for a certain maximum power that can be delivered to multiple external loads.